Apparatus to deaden the noise of typewriters



March 30,1926. 1,578,608

H. R. LUTZ-RUSSELL APPARATUS TO DEADEN- THE NOISE OF TYPEWRITERS Filed Oct. 21, 1924 l N VENTb R Hansflu do Lug-Russell WITNESSES ATTO RN EY Patented 30, 1926 U ITED "STATES PATIENT [OF I 1,578,608 FICE.

ms BUDOL F LUTZ -BU 'SSELL, OF ZURICH, SWITZERLAND.

LPPAM'IIUS '10 DELDEN THE NOISE OF TYPEWRITERS.

l i nmion'ma 0ctober'21, 1924. Serial at. 744,945.

by the impacting type during the operation thereof.

Another object is to provide a combined platen and feed-roll having the'above characteristics which maybe readily introduced into service in existing machines, without the necessity for any alterations in the latter, said platen serving to receive andfhold the paper and to feed the latter in thegusual manner, and having means whereby thecushioning effect of the. platen may be increased or decreased from the exterior without dismantling the machine or,the platen.

full and complete understanding of the invention maybe obtained from a consideration of the following detailed description, taken in connection with the accom anying drawing forming a art of this speci cation; it being underst that while the drawing shows a practical form of the invention, the latter is not to be co'nfi ned to strict conformity with the showing thereof, but may .be changed or modified,- so long as such changes or modifications mark no material departure from the salient features of the mvention, asspecifically pointed out in the nded claims.

11 the drawing, in which similar reference characters designate corresponding parts throughout the several fi res:

Figure 1 is a longitudlnal sectional View I of the improved platen.

Figure 2 isa perspective view of a portion of a typewriting machine and showing the improved platen thereon. i The combined feed-roll and platen for v typewriting machines, in the improved form,

as herein shown and described, comprises a hollow cylinder 1 formed of semi-hard rub her, and having relatively thick walls so as '-p to give the proper amount ofresiliency and yet retain the true cylindrical shape, and to just the .pawl an ratchet means (not shown).

machine for the proper functioning of the parts.

The cylinder 1 is of the same diameter and length as the existing platens insuch machines and is adapted to receive and support the sheet or sheets of paper inthe same manner and to feed the same either by means of the usual ratchet and pawl arrangement or by means of the .customary hand whee-ls generally used for the purpose.

The open ends of the cylinder 1 are each interiorly threadedfor the co-acting threads of end heads 2 and 2 respectively, which are.

formed of suitable metal and are provided with'integral, outstanding trunnions 3 and 3, centrally located and axially alined with the longitudinal axis of thecylinder. The inner faces of the heads are of concavo-convex formation to snugly receive the ends of an inner tube or bag 4 of elongated tubular form and made of soft, flexible rubber or other inflatable, material, the ends 4' and 5 being'of hen'ii-spherical form'to fit the said end heads, and thus will be supported at all points on its exterior surface by the cylinder and the heads.

The trunnion 3 is provided with a longitudinal bore or passageway 3" communicating with the interior of the cylinder 1 and extending to the outer end thereof, said bore being ada ted to receive a valve-stem 5, having suita 1c air-tight connection with the adjacent end 5 of the flexible, inflatable tube or bag 4, and adapted to conduct air,

to thesame when inflating the latter.

The outer end of the valve stem 5' extends beyond the end of the supporting trunnion 3,- and is suitably threaded for the reception of the closure cap 6 which, in addition to the action of the valve proper, serves to preventfescape of air from the inner tube or bag. The trunnions 3 and 3' are equipped withthe 'usual'hand wheels 7 forturnlnlg the platen backwardly or forwardly to a aper, in addition to the aforesaid By removing the cap 6, an ordinary pum 7 indicated in dotted lines, may be applie to the extended end of the valve stem, and the required amount ofair may be forced into the inner tube 4 which will expandv sufiiciently to reinforce the walls of the laten cylinder, and resist the force of the Impacting type-bars 8, as the machine s operated, and the cushioning efl'ect thus proretain its axial alinement inthe ffduced, Z both by reason of the fact that the cylinder is formed of. semi-hard rubber and by reason of the inclosedtube or bag of compressed air, serves to deaden the sound of such impact, roviding means for rendering the typewrltingmachine as nearly noiselessas it is possible to make the same.

' From the foregoing it will be seen that a simple and cheaply-manufactured platen has been provided for use in typewriting machines, which may be vinstalled or use in the same. manner as the existing platens,.

without any alteration in the machine, and that the sheets of paper are handled in the same manner, with the added advantage that the noise of-the hammering type-bars is almost entirely eliminated.

What is claimed is:

1'. A platen for typewriting machines, comprising a cylindrical roller formed of semi-resilient material, removable heads se.

cured in each end thereof and provided with trunnions for application to a typewriting machine, and inflatable means confined Within the cylinder and adapted to bear against all points on the inner wall thereof {)0 eliminate the noise of impacting type ars.

2. A substantially noiseless platen for typewriting machines, comprising a c lindrlcal roller formed of semi-hard ru ber,

as my own, I

removable metallic heads adapted to be screwed into each end of the cylinder, said heads each having a longitudinally-alined- Wells, removable metallic heads secured in each end of'the cylinder, each head having an axially-alined trunnion to constitute.

bearings for the cylinder and having hand wheels to turn the same, one of said tl'lllh nions being provided with a central, longi: tudinal bore, afiexible, air-tight expansible bag fitting the space within the cylinder and between the heads,.a valve stem communicating w th one end of the expansible ha and extending through the bore in sai trunnion topermit inflation of the bag and to cushion the walls, of the cylinder, against the impact hf type-bars of the said machine,

and a closure cap fitting the valve stem at, i the end of the trunnion-to prevent escape of air. v 4

In testimony that I claim the foregoing have hereto afixed my i nature.

Hans RUDOLF LU z-RussEL I V 

